I have a couple of questions in regard to a house built in the teens’s. After tearing out some cheap paneling and removing cracked plaster to get to the lath, I found another layer of plaster and lath (I think) in the stud bay about 1 1/2 inches from the interior lath. I assume that on the exterior side there is an airspace also, but don’t know for sure as it’s been -20 here in northern Minnesota and at this point I’m not going to look and see. My questions are; (1) does anyone know how this is contructed and what the reason is for doing it and (2) how in the heck do I insulate without completely gutting the interior? Any ideas would be welcome.
Regards,
Polky
Rob Polkinghorne
Littlefork, Minnesota
Replies
yes , piffen was talking about this.. but you can't insulate the stud bay if you don't take the 2d layer of plaster & lath out..
so, i'm afraid yous gots some guttin to do
I'll dig around for Piffin's posts for more info but I still don't know why this was done ... wind barrier?
Polky
Can you get it blown in to the stud bays from the ext wall? The insulators usually bore holes about 2 1/2" dia. and plug the holes in the sheathing when finished. You may have to either remove siding in a few spots, or trust the insulators to bore through it and you patch it after. Depending on your siding, I've seen some nice, nearly invisible repairs.
Don't expect (or allow) the insulation guys to do more than insulate and plug the holes and patch your vapor barrier. The ones I've worked with are not carpenters.
Jules Quaver for President 2004
Edited 2/17/2003 8:40:46 PM ET by Notchman
That was my original plan until my wife decided she wanted to carpet the second floor, went and had the first bedroom done then wanted to do the stairwell which has an outside wall. One thing led to another... and here I am. As the siding is going to be replaced, I had planned to blow in from the outside this summer. The second layer of plaster threw a crimp in the plans as I'm not sure how well it would work with only an 1 1/2" deep space to blow into. Although some insulation is better than none, 1 1/2" is definitely closer to none than it is to a full bay.
As an aside, is it just me or do all wives want to decorate before the contruction is finished?
Polky
How much plaster/lathe tearout is involved? The whole house? If so, is it reasonable to blow in what you can and then sheath the ext with rigid foam panels?
I'm out of my depth here because I live in a more moderate climate, but I recall rigid foam board being used commonly in your area.
(Just brainstorming...trying to save you some messy work around all that decorating!) :-)Jules Quaver for President 2004
That's definitely an option but requires extending all the jambs and sills on the windows and doors (older, but still serviceable), and there are quite a few. I was considering foaming one or both spaces but have not heard much about this in the last few years ... still an option? Also thought about removing the sheathing in places and sliding rigid foam sheets into the bays but probably wouldn't be able to do more than 1" of foam. Seeing as how I'm 100 miles from a town of any size, my resources as far as contractors are somewhat limited.
Polky
Polky,
I've come across this several times in Minneapolis now. I think it was an early form of insulating. creating two distinct air pockets within the stud wall. I've also seen it done with llath strips holding a layer of asphalt paper midway inside the wall cavity.
I don't know if you really have any option other than opening the walls to get effective insulation. For what it's worth, the walls are the least critical place to insulate. Attic is where you get bang for the buck. For walls, a good air seal is more important than insulation.
You are probably getting a lot of air leakage into the attic through the exterior balloon framed walls. Tell us a little more about your house.
One story? Two story? story and a half? Cape? Bungalow? kneewalls?
Steve
The house is two-story with 5 foot sidewalls on the second floor, 9 foot ceiling height on first floor dropped to eight foot with ceiling tile. It was 'remodeled' in the late '50's so the plumbing and wiring were replaced at that time with everything run between the original and the dropped first-floor ceiling. I've got a flat ceiling about 10 feet wide running the length of the house upstairs so insulating that space would help but I would imagine that there is only 6" at best above the sloped sections. My plan for the attice was to blow in as much as practical and use 1" foam board on the interior with new drywall on top of that seeing as how the wiring for the lights runs above the tile ceiling and the stripping is already there.
You know, as I was writing this, a solution occured to me. When the siding is removed, the balloon framing would allow me to remove a strip of sheathing at the top of the wall, cut out a section of the middle layer of plaster and blow in from the top for both the exterior and the interior air spaces. the only potential problem I can see is blowing insulation through a 1 1/2" or less hose. Vermiculite anyone? :-)
Polky
If I understand you right, the extra layer of plaster you have found is in the stud space closest to the interior. What I have seen is palster added right on the back side of the exterior sheathing. In that case, I can easily take it out - fewer naoils and lathe involved. That thread had someone else with a situation similar to what iot seems you have.
I'm thinking spray foam is the ticket for you and you can do it yopur self. Here's one link, other guys might have the other one.
http://farmtekcatalog.com/c/g8/p/fullpage.php?page=t112&session=1005675.
Excellence is its own reward!
The extra layer of plaster is midway between the interior and exterior; 1 1/2" air space on either side of it. I don't think do-it-yourself foam is the answer without removing either the interior or exterior or both.
Polky
Question: wiring>>>> is it still (was?) K&T? if so, that cannot be covered w/ insulation. Suggest that you upgrade ur wiring (easier to do w/o insulation to fight too) first.
Wiring was re-done in the late 50's (NM); just a few signs of the K-T that used to be there so I doubt there is any left in use.
Polky